In order to determine the water vapor adsorption performance of a rotary desiccant-based air conditioning system, the behavior of water adsorption on cylindrical pores of different sizes was studied by using classical density functional theory (CDFT) based on perturbated chain statistical associating fluid theory (PC-SAFT). Firstly, the structural parameters of the desiccant material were characterized by scanning electron microscopy (SEM), X-ray Energy Dispersive Spectrum (EDS), and N₂ adsorption/desorption isotherms, as well as adsorption equilibrium measurements of water vapor at temperature range 293–308 K. Secondly, the potential energy equation of water molecules in cylindrical pores was determined, and contribution of various terms of PC-SAFT for simulating fluid in cylindrical pores were established. Finally, the pore size distribution (PSD) of the desiccant materials is determined by the PC-SAFT kernel. Moreover, water vapor condensation was investigated with the PC-SAFT model in micropores. The results indicate that the rotary desiccant materials have a large number of micropores with a volume of 0.3669 cm³/g and the amount of water adsorption is about 0.285 g/g. The condensation pressure and the pore width corresponding to the saturated pressure P0 grow with an increase in the temperature, signifying that adjusting the PSD of the material has a significant effect on improving the dehumidification performance. The research concludes that the PSD range of the oxide cylindrical pore between 1.09 and 1.53 nm is particularly beneficial for dehumidification. This study provides valuable theoretical guidance for optimizing dehumidification materials.

Two kinds of slit pore carbon materials, namely activated carbon (AC) and 3D graphene materials (3D-GS), were purchased to examine their methane storage capabilities. The structural analysis and characterization of AC and 3D-GS were carried out using X-ray diffraction (XRD), scanning electron microscopy (SEM), the X-ray energy dispersive spectrum (EDS), and N₂ adsorption/desorption isotherms. Additionally, a thermodynamic framework was employed in the Henry’s law region to evaluate the potential well between the adsorbed fluid and adsorbent. The adsorption behavior of methane on two materials at room temperature and high pressure was also investigated. The results show that the Toth equation is the most suitable model for predicting adsorption isotherms than the Langmuir and L-F equations and determines that the absolute uptake of methane storage on AC and 3D-GS are, respectively, 7.86 mmol·g⁻¹ and 8.9 mmol·g⁻¹ at 298 K and 35 bar. In the Henry’s law region, the isosteric heat of methane adsorption on 3D-GS is larger than that of AC. Meanwhile, the potential well between methane and carbon-based materials decreases as the temperature increases. This indicates that the capacity of methane uptake is enhanced at lower temperatures, which is consistent with the measurements of adsorption isotherms. The research concludes that the 3D-GS is more suitable as a material storage medium than AC. This study provides valuable theoretical guidance for exploring the potential of methane storage on slit pore carbon-based material.

This study evaluates integrated shipboard freshwater production and fresh air pretreatment on a 20,000 TEU-class container vessel, addressing its freshwater demand and the inefficient recovery of exhaust waste heat from the main engine. The system integrates rotary dehumidification, seawater condensation, and water purification. A theoretical model was developed to evaluate the system performance, incorporating design, thermodynamic modeling, parameter optimization, and adaptability analyses under various operating conditions. The results indicate that under optimal conditions (seawater at 25 °C, outlet temperature difference of 2 °C), the single-stage system is predicted to produce approximately 1.45 m³ of freshwater per day, meeting 20.7% of the vessel’s freshwater requirement. The auxiliary electrical energy consumption, estimated based on standard engineering correlations, is 1–1.5 kWh/m³, representing a 70–80% reduction compared to conventional reverse osmosis systems (3–6 kWh/m³). The sensitivity coefficient for seawater temperature was −0.334, whereas that for output temperature was −0.167. A two-stage series configuration has the potential to further improve the demand satisfaction rate to 41–61%. Overall, the proposed system enables the cascade utilization of ship waste heat and functional integration of air pretreatment and freshwater production, offering a promising auxiliary engineering solution for energy conservation, emission reduction, and onboard freshwater self-sufficiency in marine applications.